1. Field of the Invention
The present invention relates to an image sensor unit, an image reading apparatus, an image forming apparatus, a manufacturing method of the image sensor unit, a manufacturing method of the image reading apparatus, and a manufacturing method of the image forming apparatus. Particularly, the present invention relates to an image sensor unit that reads large originals and the like, an image reading apparatus, an image forming apparatus, a manufacturing method of the image sensor unit, a manufacturing method of the image reading apparatus, and a manufacturing method of the image forming apparatus.
2. Description of the Related Art
Readable lengths (hereinafter, “read lengths”) of originals are generally about A4, B4, and A3 sizes in an image sensor unit used in an image reading apparatus, such as a facsimile and a scanner. In recent years, an elongated image sensor unit that can read large originals in A2, A1, and A0 sizes exceeding the read length of A3 size is used in an image reading apparatus, such as an electronic white board.
The image sensor unit of the image reading apparatus that reads large originals and the like exceeding the A3 size includes a plurality of rod-lens arrays shorter than the A3 size arranged in series in a main-scan direction.
For example, Patent Document 1 discloses a contact image sensor (image sensor unit) elongated by connecting a plurality of rod-lens arrays.
Patent Document 1
    Japanese Laid-open Patent Publication No. 2010-187187
In order for the rod-lens arrays arranged in a line in the main-scan direction to accurately focus reflected light from an original on sensor chips, the rod-lens arrays need to be fixed by accurately positioning the rod-lens arrays so that rod lenses of adjacent rod-lens arrays are disposed at predetermined intervals. However, there is a problem that work of accurately positioning the rod-lens arrays inserted to thin grooves of frames is significantly difficult.